1. Field of the Invention
This invention relates a print control device for thermal printers to provide for a print control device to stop printing should a problem arise.
More particularly, the invention is concerned with a method and an apparatus for controlling the amount of and the sufficient quantity of current supplied to electrical resistors associated with various parts or points of a thermal printer for control of the thermal printer head. The parts or points of the printer are those which may cause the thermal printer to provide a defective print and therefore an undesired product. In addition, a strict control is necessary to provide an indication when a particular part or mechanism of the print control device breaks down or becomes defective to prevent an incorrect printed product. Also, it is necessary to provide an indication when a part associated with the print control device becomes defective to provide a signal as soon as possible to the operating control mechanism of the thermal printer to provide an indication of the incorrect or defective operation of a defective product, part and to prevent the thermal printer from continuing its operation and thereby produce a defective product, and further to cease operation of the thermal printer.
2. Description of Related Art
One type of known print control device used by the prior art is a print control device which includes an optical sensor placed downstream with respect to the printing head of the thermal printer. An example of the aforesaid device is described in the earlier U.S. patent application Ser. No. 12/057,430, filed Mar. 28, 2009, and the subject matter thereof including the complete disclosure is incorporated herein by reference as if everything contained in the aforesaid patent application were repeated herein.
The aforesaid optical sensor in the earlier disclosure works very well and is quite useful. However, the only drawback is the cost involved because optical sensors are quite costly.
List of Alberto Campanini Applications and Patents                U.S. Pat. No. 6,798,436, issued Sep. 28, 2004 based on U.S. patent application Ser. No. 10/147,174, filed: May 8, 2002, entitled: THERMAL PRINTER CLOSING APPARATUS        U.S. Pat. No. 7,175,356, issued: Feb. 13, 2007 based on U.S. patent application Ser. No. 10/939,043 filed: Sep. 10, 2004, entitled: HEAD SUPPORT BASE FOR THERMAL PRINTER        U.S. Pat. No. 7,322,760, issued: Jan. 29, 2008 based on U.S. patent application Ser. No. 11/193,214 Filed: Jul. 29, 2005, entitled: ANTIJAMMING DEVICE FOR PRINTERS PUT IN PUBLIC PLACES        Re: U.S. patent application Ser. No. 11/272,277        Publication No.: US 2006/0152574        Filed: Nov. 10, 2005        Title: LASER WRITING HEAD FOR PRINTER        Re: U.S. patent application Ser. No. 11/581,770        Publication No.: US 2007/0166093        Filed: Oct. 16, 2006        Title: AUTOMATIC OPENING DEVICE FOR A PRINTER GATE        Re: U.S. patent application Ser. No. 11/960,956        Publication No.: US 2008/0229892        Filed: Dec. 20, 2007        Title: LIMITING DEVICE FOR ROLL PRINTER        Re: U.S. patent application Ser. No. 12/057,430        Publication No.: US 2008/0247799        Filed: Mar. 28, 2008        Title: THERMAL PRINTER HEAD WITH PRINT CONTROL DEVICE        Re: U.S. patent application Ser. No. 12/321,216        Filed: Jan. 20, 2009        Title: PRINTING ROLL RELEASE OF THE HEAD IN THE THERMAL PRINTER        Assignee: Custom Engineering Spa        